Ghost imaging, in which images are made using light that never came near the object, has now been demonstrated with reflected light, but the debate continues over whether the effect can be explained with classical physics.

New calculations show that a material with the right electrical properties could dramatically improve the efficiency of light-like waves that travel on metal surfaces. Devices based on these waves might someday process light signals on a chip.

A new technique can detect when electromagnetic waves moving through dense materials exhibit extreme changes in their behavior. It could help with surveying of geological structures or possibly scanning human bodies.